The Latest: Texas monitoring tropical weather in Gulf

Gov. Greg Abbott says Texas is preparing for a possible tropical storm system in the southeastern Gulf of Mexico.

The tropical system is one of five that have formed in the Atlantic Ocean, including hurricanes Florence and Helene, Tropical Storm Isaac and an as-yet unnamed system far off the East Coast. Abbott says Texas is keeping an eye on the system in the Gulf.

The National Hurricane Center says that system could become a tropical depression by Thursday or Friday, and that residents along both the Texas and Louisiana coasts should monitor the storm.

Florence is the most powerful and dangerous of all the weather systems. The Category 4 hurricane with 130 mph (215 kph) winds was barreling toward the coasts of North and South Carolina and has been forecast to hit land as an extremely large, powerful and dangerous storm. Some coastal residents have been ordered to evacuate.

11:30 a.m.

South Carolina Gov. Henry McMaster says he has lifted mandatory evacuation orders in three counties along the state's southern coast. McMaster made the announcement Tuesday as forecasters continued to show Hurricane Florence's projected tract moving farther northward. McMaster also said lane reversals would begin at 11 a.m. Tuesday on Interstate 26, an hour earlier than had been scheduled, allowing all lanes of the interstate to move westward, away from the coast.

10:55 a.m.

Forecasters say Florence will arrive on land as an extremely dangerous major hurricane by the end of the week.

According to the National Hurricane Center, Florence has maximum sustained winds near 130 mph (215 kph). By 11 a.m. Tuesday, Florence was centered about 905 miles (1,455 kilometers) east-southeast of Cape Fear, North Carolina, and moving west-northwest at 16 mph (25 kph). Its center will move between Bermuda and the Bahamas on Tuesday and Wednesday, then approach the coast of South Carolina or North Carolina.

Two other storms are spinning in the Atlantic as the 2018 hurricane season peaks: Tropical Storm Isaac is approaching the Caribbean, while Hurricane Helene is no threat to land over waters. As Isaac approaches the Caribbean, hurricane watches are in effect for Guadeloupe, Martinique and Dominica, while a tropical storm watch was issued for Antigua and Montserrat.

10:50 a.m.

The Navy has authorized an emergency evacuation order ahead of the arrival of Hurricane Florence.

Rear Adm. Charles Rock is commander of Navy Region Mid-Atlantic. He said in a statement Tuesday that the safety of personnel and families is his top priority now.

The order follows Virginia's evacuation order and remains in effect until Sept. 16. So far, state officials' tiered system only requires residents of the most flood-prone areas, known as "Zone A," to leave their homes.

The Navy's order applies to Navy and civilian personnel, dependents of active-duty service members and reservists on active duty living in Hampton Roads and Zone A.

The Navy says Region Mid-Atlantic evacuees are authorized to proceed within 500 miles (805 kilometers) of the designated remote safe haven area of Asheville, North Carolina. Others should head to the remote safe haven area designated by their parent chain of command.

10:50 a.m.

The Virginia Department of Corrections has evacuated inmates from a coastal prison as Hurricane Florence approaches the East Coast.

The department said in a statement Tuesday that the Indian Creek Correctional Center in Chesapeake was evacuated Monday night after Gov. Ralph Northam issued a mandatory evacuation order for some of the state's lowest-lying coastal areas. The medium-security facility provides treatment programs for substance-abusing offenders.

The department also says all visitation statewide is canceled for Saturday and Sunday.

The National Hurricane Center says Florence is expected to approach the coast of North or South Carolina on Thursday, but Virginia is also under a state of emergency. Officials say the state is expecting a coastal storm surge, high wind, inland flooding and widespread power outages.

10:50 a.m.

The Democrat running to be South Carolina's next governor has been called up for guard duty as the state prepares for the arrival of Hurricane Florence.

Campaign spokesman Brad Warthen tells The Associated Press that James Smith has been activated as part of his service as a major in the South Carolina Army National Guard.

Warthen didn't know specifically where Smith had been stationed, but the Army says guardsmen typically help when traffic patterns are altered for evacuations.

Gov. Henry McMaster has ordered the evacuation of South Carolina's coastline. State troopers are clearing eastbound lanes of Interstate 26 so that they could be reversed later Tuesday.

Smith is challenging McMaster in this fall's election. On Monday, both candidates suspended their campaigns as the state gets ready for the storm.

The Army says the South Carolina National Guard has mobilized about 1,600 soldiers and airmen to prepare for Hurricane Florence.

10:45 a.m.

South Carolina's governor has ordered more than a million people living along the state's coast to evacuate ahead of Hurricane Florence.

Gov. Henry McMaster says he's preparing the state for winds as powerful as Hurricane Hugo, which plowed inland nearly 30 years ago and caused devastating damage.

McMaster said on CNN Tuesday that officials are "taking nothing for granted" with Florence predicted to make landfall Thursday. The storm is so huge that South Carolina won't be spared even if it escapes the eye of the hurricane.

The evacuation order becomes mandatory at noon Tuesday, but cameras show traffic already backing up along the main interstate connecting Charleston and Columbia.

10:30 a.m.

National Hurricane Center Director Ken Graham is warning that the "staggering" size of Florence means its impacts will be felt far and wide.

Forecasters say hurricane-force winds extend up to 40 miles (65 kilometers) from the center of Hurricane Florence, and tropical storm-force winds reach up to 150 miles (240 kilometers) from its eye.

That means the hurricane will be dumping rain over multiple East Coast states, and it's not just a coastal problem. With torrential rains in the Appalachian mountains, that water could easily cause flash floods.

10:20 a.m.

President Donald Trump is canceling a campaign rally in advance of Hurricane Florence's landfall.

His campaign says it's canceling a Thursday event in Cape Girardeau, Missouri, where he had been scheduled to stump for the Republican senate candidate, state attorney general Josh Hawley.

The campaign said the event was scuttled out of safety concerns. It was the second rally Trump cancelled this week due to the storm, following a Friday rally slated for Mississippi.

The massive hurricane is closing in on the Carolinas and Virginia and could cause disastrous weather as far as Pennsylvania and Ohio.

8 a.m.

The National Hurricane Center says a new report from an Air Force Reserve Unit hurricane hunter aircraft indicates that Hurricane Florence's top sustained winds have decreased slightly to 130 mph (215 kph), with higher gusts.

Florence is still a Category 4 hurricane and is expected to regain its top wind strength in the next day or so. It remains an extremely dangerous major hurricane through Thursday night.

The 8 a.m. forecast changes the storm surge watch for the eastern United States, with the worst impact, a surge of up to 12 feet, expected on a stretch from Cape Fear to Cape Lookout in North Carolina. It says total rainfall could reach 30 inches in some places, prompting life-threatening flash flooding from South Carolina to Northern Virginia.

5:20 a.m.

Hurricane Florence has slightly increased in speed as it heads toward the U.S. East Coast.

The National Hurricane Center said Tuesday morning that Florence is moving toward the west-northwest near 15 mph (24 kmh) and the storm will continue a slight increase in speed during the next couple of days.

The Miami-based center says the storm's center was located about 410 miles (660 kilometers) south of Bermuda and about 975 miles (1570 kilometers) east-southeast of Cape Fear, North Carolina.

Maximum sustained winds were clocked at 140 mph (220 kph) as it moved west-northwest at 13 mph (20 kph).

Florence is expected to be an extremely dangerous major hurricane through Thursday night.

11:10 p.m.

Hurricane Florence continues to grow in size and magnitude as it barrels toward the U.S. East Coast.

The National Hurricane Center said Monday the monster storm will be close to Category 5 strength by Tuesday. A Category 5 storm has the potential to cause catastrophic damage.

"The bottom line is that there is high confidence that Florence will be a large and extremely dangerous hurricane, regardless of its exact intensity," the hurricane center said. Florence was a Category 4 storm late afternoon Monday.

At 11 p.m. EDT, the storm's center was located about 465 miles (750 kilometers) south-southeast of Bermuda and about 1,085 miles (1745 kilometers) east-southeast of Cape Fear, North Carolina.

Maximum sustained winds were clocked at 140 mph (220 kph) as it moved west-northwest at 13 mph (20 kph).

Some strengthening is expected during the next 36 hours, and Florence is expected to be an extremely dangerous major hurricane through Thursday.